#!/bin/bash
 # Copyright (C) Martin Schlemmer <azarah@nosferatu.za.org>
 # Copyright (C) 2006 Sam Ravnborg <sam@ravnborg.org>
 #
 # Released under the terms of the GNU GPL
 #
 # Generate a cpio packed initramfs. It uses gen_init_cpio to generate
 # the cpio archive, and then compresses it.
 # The script may also be used to generate the inputfile used for gen_init_cpio
 # This script assumes that gen_init_cpio is located in usr/ directory
 
 # error out on errors
 set -e
 
 usage() {
 cat << EOF
 Usage:
 $0 [-o <file>] [-u <uid>] [-g <gid>] {-d | <cpio_source>} ...
         -o <file>      Create compressed initramfs file named <file> using
                        gen_init_cpio and compressor depending on the extension
         -u <uid>       User ID to map to user ID 0 (root).
                        <uid> is only meaningful if <cpio_source> is a
                        directory.  "squash" forces all files to uid 0.
         -g <gid>       Group ID to map to group ID 0 (root).
                        <gid> is only meaningful if <cpio_source> is a
                        directory.  "squash" forces all files to gid 0.
         <cpio_source>  File list or directory for cpio archive.
                        If <cpio_source> is a .cpio file it will be used
                        as direct input to initramfs.
         -d             Output the default cpio list.
 
 All options except -o and -l may be repeated and are interpreted
 sequentially and immediately.  -u and -g states are preserved across
 <cpio_source> options so an explicit "-u 0 -g 0" is required
 to reset the root/group mapping.
EOF
 }
 
 # awk style field access
 # $1 - field number; rest is argument string
 field() {
         shift $1 ; echo $1
 }
 
 list_default_initramfs() {
         # echo usr/kinit/kinit
         :
 }
 
 default_initramfs() {
         cat << EOF >> ${output}
                 # This is a very simple, default initramfs
 
                 dir /dev 0755 0 0
                 nod /dev/console 0600 0 0 c 5 1
                 dir /root 0700 0 0
                 # file /kinit usr/kinit/kinit 0755 0 0
                 # slink /init kinit 0755 0 0
EOF
 }
 
 filetype() {
         local argv1="$1"
 
         # symlink test must come before file test
         if [ -L "${argv1}" ]; then
                 echo "slink"
         elif [ -f "${argv1}" ]; then
                 echo "file"
         elif [ -d "${argv1}" ]; then
                 echo "dir"
         elif [ -b "${argv1}" -o -c "${argv1}" ]; then
                 echo "nod"
         elif [ -p "${argv1}" ]; then
                 echo "pipe"
         elif [ -S "${argv1}" ]; then
                 echo "sock"
         else
                 echo "invalid"
         fi
         return 0
 }
 
 list_print_mtime() {
         :
 }
 
 print_mtime() {
         local my_mtime="0"
 
         if [ -e "$1" ]; then
                 my_mtime=$(find "$1" -printf "%T@\n" | sort -r | head -n 1)
         fi
 
         echo "# Last modified: ${my_mtime}" >> ${output}
         echo "" >> ${output}
 }
 
 list_parse() {
         [ ! -L "$1" ] && echo "$1 \\" || :
 }
 
 # for each file print a line in following format
 # <filetype> <name> <path to file> <octal mode> <uid> <gid>
 # for links, devices etc the format differs. See gen_init_cpio for details
 parse() {
         local location="$1"
         local name="${location/${srcdir}//}"
         # change '//' into '/'
         name="${name//\/\///}"
         local mode="$2"
         local uid="$3"
         local gid="$4"
         local ftype=$(filetype "${location}")
         # remap uid/gid to 0 if necessary
         [ "$root_uid" = "squash" ] && uid=0 || [ "$uid" -eq "$root_uid" ] && uid=0
         [ "$root_gid" = "squash" ] && gid=0 || [ "$gid" -eq "$root_gid" ] && gid=0
         local str="${mode} ${uid} ${gid}"
 
         [ "${ftype}" == "invalid" ] && return 0
         [ "${location}" == "${srcdir}" ] && return 0
 
         case "${ftype}" in
                 "file")
                         str="${ftype} ${name} ${location} ${str}"
                         ;;
                 "nod")
                         local dev=`LC_ALL=C ls -l "${location}"`
                         local maj=`field 5 ${dev}`
                         local min=`field 6 ${dev}`
                         maj=${maj%,}
 
                         [ -b "${location}" ] && dev="b" || dev="c"
 
                         str="${ftype} ${name} ${str} ${dev} ${maj} ${min}"
                         ;;
                 "slink")
                         local target=`readlink "${location}"`
                         str="${ftype} ${name} ${target} ${str}"
                         ;;
                 *)
                         str="${ftype} ${name} ${str}"
                         ;;
         esac
 
         echo "${str}" >> ${output}
 
         return 0
 }
 
 unknown_option() {
         printf "ERROR: unknown option \"$arg\"\n" >&2
         printf "If the filename validly begins with '-', " >&2
         printf "then it must be prefixed\n" >&2
         printf "by './' so that it won't be interpreted as an option." >&2
         printf "\n" >&2
         usage >&2
         exit 1
 }
 
 list_header() {
         :
 }
 
 header() {
         printf "\n#####################\n# $1\n" >> ${output}
 }
 
 # process one directory (incl sub-directories)
 dir_filelist() {
         ${dep_list}header "$1"
 
         srcdir=$(echo "$1" | sed -e 's://*:/:g')
         dirlist=$(find "${srcdir}" -printf "%p %m %U %G\n")
 
         # If $dirlist is only one line, then the directory is empty
         if [  "$(echo "${dirlist}" | wc -l)" -gt 1 ]; then
                 ${dep_list}print_mtime "$1"
 
                 echo "${dirlist}" | \
                 while read x; do
                         ${dep_list}parse ${x}
                 done
         fi
 }
 
 # if only one file is specified and it is .cpio file then use it direct as fs
 # if a directory is specified then add all files in given direcotry to fs
 # if a regular file is specified assume it is in gen_initramfs format
 input_file() {
         source="$1"
         if [ -f "$1" ]; then
                 ${dep_list}header "$1"
                 is_cpio="$(echo "$1" | sed 's/^.*\.cpio\(\..*\)\?/cpio/')"
                 if [ $2 -eq 0 -a ${is_cpio} == "cpio" ]; then
                         cpio_file=$1
                         echo "$1" | grep -q '^.*\.cpio\..*' && is_cpio_compressed="compressed"
                         [ ! -z ${dep_list} ] && echo "$1"
                         return 0
                 fi
                 if [ -z ${dep_list} ]; then
                         print_mtime "$1" >> ${output}
                         cat "$1"         >> ${output}
                 else
                         cat "$1" | while read type dir file perm ; do
                                 if [ "$type" == "file" ]; then
                                         echo "$file \\";
                                 fi
                         done
                 fi
         elif [ -d "$1" ]; then
                 dir_filelist "$1"
         else
                 echo "  ${prog}: Cannot open '$1'" >&2
                 exit 1
         fi
 }
 
 prog=$0
 root_uid=0
 root_gid=0
 dep_list=
 cpio_file=
 cpio_list=
 output="/dev/stdout"
 output_file=""
 is_cpio_compressed=
 compr="gzip -9 -f"
 
 arg="$1"
 case "$arg" in
         "-l")   # files included in initramfs - used by kbuild
                 dep_list="list_"
                 echo "deps_initramfs := \\"
                 shift
                 ;;
         "-o")   # generate compressed cpio image named $1
                 shift
                 output_file="$1"
                 cpio_list="$(mktemp ${TMPDIR:-/tmp}/cpiolist.XXXXXX)"
                 output=${cpio_list}
                 echo "$output_file" | grep -q "\.gz$" && compr="gzip -9 -f"
                 echo "$output_file" | grep -q "\.bz2$" && compr="bzip2 -9 -f"
                 echo "$output_file" | grep -q "\.lzma$" && compr="lzma -9 -f"
                 echo "$output_file" | grep -q "\.cpio$" && compr="cat"
                 shift
                 ;;
 esac
 while [ $# -gt 0 ]; do
         arg="$1"
         shift
         case "$arg" in
                 "-u")   # map $1 to uid=0 (root)
                         root_uid="$1"
                         shift
                         ;;
                 "-g")   # map $1 to gid=0 (root)
                         root_gid="$1"
                         shift
                         ;;
                 "-d")   # display default initramfs list
                         default_list="$arg"
                         ${dep_list}default_initramfs
                         ;;
                 "-h")
                         usage
                         exit 0
                         ;;
                 *)
                         case "$arg" in
                                 "-"*)
                                         unknown_option
                                         ;;
                                 *)      # input file/dir - process it
                                         input_file "$arg" "$#"
                                         ;;
                         esac
                         ;;
         esac
 done
 
 # If output_file is set we will generate cpio archive and compress it
 # we are carefull to delete tmp files
 if [ ! -z ${output_file} ]; then
         if [ -z ${cpio_file} ]; then
                 cpio_tfile="$(mktemp ${TMPDIR:-/tmp}/cpiofile.XXXXXX)"
                 usr/gen_init_cpio ${cpio_list} > ${cpio_tfile}
         else
                 cpio_tfile=${cpio_file}
         fi
         rm ${cpio_list}
         if [ "${is_cpio_compressed}" = "compressed" ]; then
                 cat ${cpio_tfile} > ${output_file}
         else
                 (cat ${cpio_tfile} | ${compr}  - > ${output_file}) \
                 || (rm -f ${output_file} ; false)
         fi
         [ -z ${cpio_file} ] && rm ${cpio_tfile}
 fi
 exit 0
